Video issues with Sierra beta/GM

In the GM of Sierra, I have been running into spotty video issues. For instance, on sites like Deadspin where they embed videos from other websites, the videos will load, and then when they finish playing they crash the page and require one or two page reloads for the page to become responsive again. Not all videos show this behavior; on Youtube for instance I can watch the videos directly for the most part without issue. However, if I watch that video embeded on another website I will see this issue. Again, this issue cropped up when I changed to running Sierra instead of El Cap as the OS. I have tried disabling all extensions, creating a brand new profile, and pretty much every single vivaldi flag I have seen mentioned as a possible fix for video issues to no avail. I have also tried both the snapshots and the latest stable of Vivaldi, and have experienced the same issue in every version I have tried. This is with flags both set to default and tweaked, or with a new profile or my current regular profile.

The real question is why you installed Sierra beta in the first place. It only makes sense if you are a developer and need to test your applications/software to get them ready for the new release. I see so many people install operating systems ahead of time, and it makes no sense at all – problems are to be expected. I just wouldn't recommend going through the pain and suffering if you have no reason to. Normally you should wait at least till the .2 or .3 release until you install/upgrade. Then most applications work out of the box and the biggest issues are fixed.

As you said, I am a developer and I also consult for multiple companies where I need to check these sorts of things out. So it's basically part of my job. This also exists in the GM, so I'm sure quite a few people will start to run into it.

Anyway, something has changed behind the scenes. I assume this is some sort of interaction with a particular way some videos like Vine etc embed when shared within certain websites, the Vivaldi code, and the Sierra video drivers used in certain Mac configurations.